its screamed in hatred when a trans person majorly women is being attacked raped or murdered its also one of the most common thing that is yelled at a person in abuse or when they are being told they are a lesser human being its an othering word majority against a minority with a negative implication its used to offend cis women to say they are ugly look like a man and dont know how to dressactbe like a woman this is a clear indicator of the way its used against trans women try looking up the word tranny on google images youll get a telling example of the way it is used bonus points for taking off safe search